Nano-imprint patterning (NIP) process is widely considered as a promising patterning process or method that offers various features and benefits such as high resolution, high critical dimension (CD) uniformity, and relatively low cost of manufacturing when being compared with other traditional patterning processes or methods such as, for example, the commonly used lithographic exposure based patterning process. The process of current NIP method generally includes first creating a pattern in a resist layer by pressing a mold into the resist layer to shape the resist layer into the desired pattern, and then transferring the pattern directly from the resist layer to the underneath substrate.
Nevertheless, current NIP process is also known, in general, as having a relatively high defect rate due to, for example, impurity of material and/or imperfection of the process or tools. The defects have been mainly observed in two categories: 1) randomly distributed defects and 2) repeated defects. More specifically, randomly distributed defects may include, for example, particle-associated defects, gap or void associated defects, separation related defects, and defects due to residual after imprint, all of which are not repeatable in terms of location and amount. For example, gap associated defect may be induced by incomplete contact between mold and imprinting material such as resist. Repeated defects may include those that are caused by existing defects on mold and/or on substrate. For example, defects in a mold may be reflected repeatedly in patterns manufactured by using that same mold. The above issues relating to defects in the current NIP process are impeding the practical and wide use of this otherwise promising technology in semiconductor device manufacturing.